In a class action filed Thursday in U.S. District Court, Barbe Puro of Shakopee, Minn., claimed she developed symptoms of meningitis after receiving a spinal injection of methylprednisolone acetate tainted with fungus.

The drug, a steroid used to treat back and joint pain, was made by the New England Compounding Center in Framingham, Mass. Fifty sealed vials of the drug, obtained by the U.S. Food and Drug Administration, were found to contain fungus. The company has recalled all its products and shut down operations.

Puro is one of roughly 14,000 people believed to have been exposed to the suspect steroid. The U.S. Centers for Disease Control and Prevention confirmed that 185 people in 12 states have contracted fungal meningitis after spinal injections of the steroid. One person has contracted a joint infection after receiving an injection for ankle pain.

Seventy-six clinics in 23 states that received methylprednisolone acetate from the recalled lots have been instructed to notify all affected patients. The "potentially contaminated injections were given starting May 21, 2012," according to the CDC.

Puro claimed she received a spinal steroid injection Sept. 17 and developed headaches and nausea -- subtle symptoms of fungal meningitis. The following week, she received a call from the clinic that administered the shot, saying she might be at risk for fungal meningitis. The results of her spinal tap, a diagnostic test for meningitis, are pending, according to the lawsuit.

Puro filed the class action on behalf of all patients in Minnesota who received the recalled steroid. So far, the state has three known cases of infection and no reported deaths. Infections have also been reported in Tennessee, Michigan, Virginia, Indiana, Maryland, Florida, North Carolina, Ohio, New Jersey, Idaho and, most recently, Texas.

For a full list of clinics receiving the recalled lots of spinal steroid injections, click here.

Meningitis affects the membranous lining of the brain and spinal cord. Early symptoms of fungal meningitis, such as headache, fever, dizziness, nausea, sensitivity to light, stiff neck, weakness or numbness, slurred speech and pain, redness or swelling at the injection site can take more than a month to appear.

The longest duration from the time of injection to the onset of symptoms in the current outbreak is 42 days, according to the CDC's Dr. Benjamin Park.

"But we want to emphasize that we don't know what the longest will be," he said, adding that patients who received injections of the recalled drug should stay attuned to the subtle symptoms "for months."